Rotary bomb bay door with bomb releasing means



April 14, 1953 A. T. WOOLLENS ET AL 4,

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS Filed Nov. 20, 1950 8 Sheets-Sheet 1 LBERT 7-. W0 aLLE/vs,

WERNER BUM/7L,

April 1953 A. T. WOOLLENS ET AL 2,634,656

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 8 Sheets-Sheet 2 Filed Nov. 20, 1950 INVENTORS flLBERT TWOOLLE/KS.

WERNER BUG/FL, BY Maw. ATTORNEY April 14, 1 53 A. T. WOOLLENS Er AL 2,634,656

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 8 Sheets-Sheet 3 Filed NOV. 20, 1950 INVENTOR WERNER Bl/CH/ZL,

ATTORNEY April 14, 1953 A. T. WOOLLENS ET AL 2,634,656

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 8 Sheets-Sheet 4 Filed NOV. 20, 1950 l N VENTORS c7'45 )?7 TWOOLLEAAS,

WERNER BUM/7L. I

ATTORNEY April 14, 1953 A. T. WOOLLENS ET AL 2,634,655

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 8 Sheets-Sheet 5 Filed Nov. 20, 1950 IN VENTORS 7L5E/?7 TWOOLLEA/S,

IVER/YER 5007/74,

z A 01m April 14, 1953 A. T. WOOLLENS El AL 2,634,656

ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 8 Sheets-Sheet 7 Filed NOV. 20, 1950 INVENTORS BER?- 7'. W004 LENS,

4/ER/VE/P Bl/CHHL,

BY gifi E A ORN- Y A. T. WOOLLENS El AL 2,634,656

April'14, 1953 ROTARY BOMB BAY DOOR WITH BOMB RELEASING MEANS 's Sheets-Sheet 8 Filed Nov. 20, 1950 mi M Ma ,m. WW, 2

Patented Apr. 14, 1953 ROTARY BOMB BAY DOOR WITH BOlWB RELEASING MEANS Albert '1. Woollens, Baldwin, and Werner Buchal, Bel Air, MIL, assignors to The Glenn L. Martin Company, Middle River, Md., a corporation of Maryland Application November 20, 1950, Serial No. 196,560

3 Claims. 1

This invention relates to an improved bomb bay construction for aircraft.

As the speeds of aircraft have gone higher and higher, the problem of providing means for effective and accurate bombing has been correspondingly increased. With the conventional bomb bay, the bombs are normally housed within the bomb bay, being carried by suitable bomb shackles attached to the interior structure of the fuselage. The bomb bay opening in the ventral portion of the fuselage is ordinarily closed by a pair of bomb bay doors which are adapted to swing outwardly to permit dropping of the bombs through the opening. With this arrangement, there is formed in the bottom of the fuselage, a relatively large opening which, at high speeds, causes extremely turbulent flow of the air. In fact, it is found that at high speeds, the air is so turbulent in and around the bomb bay opening that bombs released from their shackles in ordinary fashion, will actually tumble around inside the bomb bay, an obviously dangerous situation. Moreover, the bomb bay opening and the protruding bomb bay doors cause a very great increase in drag tending to slow down the airplane during the critical bomb run.

It is an object of this invention to provide a bomb bay and bomb carrying door therefor which will overcome the objectional features above discussed.

It is a further object of this invention to provide an arrangement of bomb bay and bomb bay door wherein the bomb bay opening may be maintained closed during the critical bombing run.

Another object is to provide such a bomb bay door wherein the bomb load is directly carried by the bomb bay door itself.

A further object is to provide a load carrying door adapted normally to carry a desired load,

such as bombs, for example, within a load carrying compartment of an airplane, said door being readily removable from the airplane and being capable of use as a pallet for ground handling of the load.

A still further object is to provide a bomb carrying door which can be rotated between normal position wherein the bombs are located within the bomb bay portion of the aircraft, and a bombing position wherein the bombs are located exterior of the aircraft, and in each of which positions the bomb bay opening will be completely closed.

A still further object is to provide means in conjunction with such a bomb carrying door for positively ejecting the bombs outwardly away from the aircraft and for controlling the rearward movement of the bomb relative to the aircraft during its initial outward movement.

Further and other objects will become apparent from the following description and claims when considered in conjunction with the appended drawings.

In the drawing:

Figure 1 is a perspective view of the mid-section of an airplane showing thhe bomb bay door of this invention being hoisted into operative position.

Figures 2, 3 and 4 are transverse sectional views showing the door actuating apparatus in various operative positions.

Figure 5 is a longitudinal section taken on line 55 of Figure 2.

Figure 6 is a fragmentary view looking rear- Waroly toward the front end of the bomb bay door.

Figure 7 is a similar view looking forwardly toward the rear end of the bomb bay door.

Figure 8 is a transverse section through the bomb bay door showing the door in inverted position with bombs suspended therefrom.

Figure 9 is a fragmentary sectional view of the bomb bay door taken on line 99 of Figure 8 and showing the bomb carrier in bomb supporting position.

Figure 10 is a similar view showing the bomb carrier in released position.

Figure 11 is a perspective view of the bomb bay door carrying bombs both internally and externally thereof.

Figure 12 is a side view of a modified bomb bay door, showing the door in inverted position on the ground.

Figure 13 is an enlarged fragmentary view of the bomb bay door of Figure 12 showing the manner of attaching the castors and tow-bar.

Figure 14 is an enlarged fragmentary view showing the manner of attaching the bomb to the door of Figure 12.

Figure 15 is a front end view of the door of Figure 12 in normal upright position in the airplane.

Figure 16 is a perspective view of a bomb bay door arranged for carrying rockets.

Turning first to Figure 1 there is shown the mid-portion of the fuselage l of an airplane 2. Forwardly and rearwardly of the center of gravity of the airplane, the underportion of the fuselage is provided with a pair of wheel well covers 3 adapted to cover conventional bicycle-type landing gear (not shown) when the airplane is in '2 flight. The lower portion of the fuselage between the forward and rearward wheel wells is formed to provide a bomb bay 4 opening through the lower side of the fuselage and adapted to be closed by a bomb bay door 5.

Bomb bay door 5 is, as will hereinafter be set forth, readily removable from the fuselage and serves both as a bomb carrying dolly or pallet for ground handling of the bomb and as a closure for the bomb bay during flight. The bomb bay door is rotatably supported from the aircraft by means of a pair of trunnions 6 and I each carried by a rock shaft 8 mounted for rotation in suitable bearings carried by bulkheads 8 and in adjacent the opposite ends of the bomb bay. The rearward trunnion 6, best shown in Figures 5 and 'I, is pivoted to rock shaft 8 as at H and has its lateral end portions 12 rounded so as to fit snugly between a pair of spaced guides 13 rigidly carried by the rearward end of the bomb bay door. Locking pins 44 are slidably carried by the guides l3 and are adapted to project into mating sockets i5 carried in the lateral end portions 12 of the trunnion.

Forward trunnion i (see Figure 6) includes a pair of yoke-shaped members 15 and i! each of which is pivoted at It to the rock shaft 8 and has its outer end portion rounded as at is so as to fit snugly between a second pair of guide members [3 carried by the forward end of the bomb bay door. The socket for the reception of the locking pin 14 is, in this case, arranged to provide for slight universal motion. To this end a partial spherical bearin member 26 is carried in a suitable seat 21 and a resilient cushion 22 is provided to resiliently oppose relative movement of the member 20 with respect to the trunnion H. The locking pin [4 is adapted to project into a mating opening 23 in the bearing element 20.

To actuate the locking pins l4, a link 24 is pivotally connected to the outer end of each pin and has its other end pivotally connected to an actuating panel 25 pivoted at 26 to the bomb bay door '5. The outer surface of panel 25 forms a continuation of the outer skin of the bomb bay door when the locking pins are in the engaged position as shown in solid lines in Figure 6. The outer ends of panels 25 are provided with rollers 21 adapted to engage detents 23 pivoted at 29 to the bomb bay door and adapted to hold the panels in their released position. Spring units 33 are provided to urge the detents into positive engagement with the rollers 2'1.

Actuatin means 3| is provided between the bulkheads 9 and for swinging rock shaft 8 together with bomb bay door 5 through a full 180 between the normal position shown in Figure 2 and the fully inverted position shown in Figure 4. The door actuating means includes a fluid pressure actuator 32 pivoted at 33 to the bulkheads and having its piston rod pivoted at 34 to the free end of lever 35 which in turn is pivoted between the bulkheads at 36. Link 31 is connected between the pivot 35 and the free end of a crank arm 38 rigid with the shaft 8. A suitable compressed air spring 39, pivotally carried at 40 between the bulkheads 9 and i5, is provided to assist the actuator 32 at certain times during the cycle of operation and is so arranged as to tend to hold the mechanism in either of its extreme positions.

With the rotary door of this invention, the bombs 4| are rigidly carried thereon by releasable bomb carriers 42. As best shown in Figures 9 and 10, each carrier comprises a conventional bomb shackle 43 rigidly fixed to the side of one of the channels 44 formed on the inner face of the bomb bay door. Each of the shackles 43 includes a pair of hook-like members 45 and 45 which are pivotally carried at H but which are normally held against rotation about these pivots by the conventional mechanism provided with such shackles. The hook members may be released in conventional fashion by the usual solenoids (not shown). Rigidly attached to the ends of the shackle 43 are a pair of adaptor brackets 48 and 49 each of which includes a bomb ejection cylinder 50 having its plunger 5i adapted to engage a bomb 4| carried thereby. Pivoted at 52 to the bracket 49 is a hook 53 having an upstanding eye 54 adapted to be engaged by the hook member 45 of the shackle 43. Hook 53 is arranged to engage the rear bomb lug 55 of the bomb H. A spring biased latch 56 pivotally carried at '51, serves to prevent accidental release of the bomb lug 55 from the hook member 53 until such time as the solenoids are actuated to release the bomb. Also pivotally carried at 51 is a swinging arm 58 having its free end formed as a hook 59 and provided with an upstanding eye 60 adapted to be engaged by the hook member 45 of the bomb shackle 43. Hook 59 is arranged to engage the forward bomb lug 6| of the bomb. As best shown in Figure 8, adjustable chocks 62 are carried by the bomb bay door and are adapted to be brought into engagement with the outer surface of the bomb so as to co-act with the carrier 42 to hold the bomb in rigid relationship to the bomb bay door. Ejection cylinders 50 are adapted to be connected by suitable conduits 63 to a compressed air cylinder 64 carried within the bomb bay door structure as shown in Figure 8,. Suitable valves (not shown) will be provided to charge the ejection cylinders from the stora e cylinder 64 after the bombs have been attached to the bomb bay door. The electrical connections to the various bomb shackles are cabled together as at 65 (Figure 5) and include a readily detachable plug and receptacle assembly 66 and 61 adjacent the end portion of the door 5.

As shown in Figures 2 to 5, suitable flexible seals 68 are provided along the longitudinal edges of the bomb bay opening, while other flexible seals 69 are provided on the end portions of the bomb bay door so as to eliminate any objectionable discontinuity in the surface of the fuselage.

As was previously mentioned, the bomb bay door of this invention is readily releasable from the aircraft and is adapted to serve as a dolly for the ground handling of the bomb load. As best shown in Figure 1, a plurality of detachable caster assemblies 10 are provided for supporting the bomb bay door from the ground so that it may be moved thereover when detached from the airplane. To facilitate towing the door, a jointed tow-bar H is adapted to be detachably connected to the underside of the forward end of the door. In normal practice, the door with its castors and tow-bar attached will be loaded on the ground and the loaded door will then be wheeled into position beneath the bomb bay of the airplane. To hoist the bomb bay door into position in the airplane, a plurality of conventional bomb hoists 72 are temporarily attached to suitable fittings 13 in the interior of the fuselage. In the instant case, a single hoist is provided at the forward end and has its hoist cable 14 reeved about a. sheave assembly 1'5 carried on the forward swingable portion 16 of the tow-bar. Adjacent the rear portion of the bomb bay, the fuselage is provided with a pair of hinged access panels 16 that may be swung outwardly to permit the insertion, one on each side, of a pair of bomb hoists, each having a hook 11 attached to its hoist cable and adapted to engage the underside of the bomb bay door adjacent the rear castors. By simultaneous operation of these three hoists, the loaded bomb bay door is lifted clear of the ground, after which the castors are removed, and the pin-actuating panels 25 swung to their released position to fully retract the locking pins Hi. The actuating mechanism has meanwhile been operated to its doorclosed position shown in Figure 2 and under these conditions, continued operation of the hoists will bring the guides [3 on the ends of the bomb bay door into mating engagement with the trunnions and I. When the parts are brought into proper alignment, actuating panels are swung into their normal flight position so as to project the locking pins [4 into sockets l5 and 23 in the ends of the trunnions. Suitable readily releasable fasteners 19 are provided to insure against accidental release of the actuating panels 25. Once the door is thus attached to the trunnions, the hoists may be removed and the draw bar detached from the underside of the door. It should be noted that during the hoisting operation, the upper end of the draw bar will project upwardly into the forward wheel well and thus will not interfere with the movement of the door to its proper position.

As indicated in Figures 11 to 16, several alternative arrangements are possible without departing from the basic concept of this invention. Thus, Figur 11 shows an arrangement wherein bombs may be carried both internally and externally of the door. In this arrangement, the internal bombs 80 are supported substantially as previously described. The outer bombs 8| are slung beneath the bomb bay door after the latter is in operative position in the airplane and are adapted to have their bomb lugs 82 project through suitable openings 83 provided by removable panels (not shown) in the undersurface of the bomb bay door and into engagement with a bomb carrier 84 carried within the door structure. With such an arrangement, the external bombs will first be released and the door will then be rotated to its inverted position and the other bombs released.

Figures 12 and 15 show a modified bomb bat door 85 adapted to carry an extremely large bomb 86. In this case the bomb itself is of such size as to protrude below th normal limit of the bomb bay. The bomb bay door 85 is therefore formed with its underside bowed downwardly so as to compensate for the larger dimensions of such a bomb. Like the previously described door 5, the bomb bay door 85 is supported from the trunnions 6 and l and is adapted to be rotated just prior to the bomb run to its inverted bombing position.

Due to the tremendous size and wei ht of such a bomb, it would not be feasible to load the door in the same fashion as with the smaller bombs. In this case, the bomb bay door is provided with a plurality of castor supporting brackets 81 on its inner face. The castors I0 are attached to these brackets as shown in Figures 12 and 3 and the bomb bay door is moved around on the ground in inverted position. To load the door, the inverted bomb bay door is moved to the 10- cality of the bomb which is lying on the ground with. its fins removed and with its lugs 88 extending upwardly and having a bomb shackle 89 attached thereto. The door is then lifted by one end, moved on its Other castors to a position over the bomb and then lowered again onto the ground so as to straddle the bomb. The bomb shackle 89 (see Figure 14) is provided at its ends with a pair of threaded sleeves 90 p oted to the side of the bomb shackle as at 9|. The bomb bay door is provided on its outer surface with a removable panel 92 through which an attaching bolt 93 may be inserted and brou into threaded engagement with th sleeve carried by the shackle 89. Bolt 93 has a spherical head portion 94 adapted to seat in a mating socket in cross member 95 rigidly carried by the bomb bay door. The bolt 93 is of sufilcient length so that when the bomb bay door 85 is supported by its castors resting on the ground, the bolt will extend into engagement with the sleeve of a bomb shackle carried by a bomb also restin on the ground. By simultaneously screwing the bolts 93 into their respective sleeves 90, the bomb shackle together with the bomb will be raised into the interior of the bomb bay door until such time as the shackle engages the cross members 95 or other suitable stops. Suitable adjustable chocks (not shown) will of course be provided for preventing any undesired side sway of the bomb relative to the bomb bay door. The loaded bomb bay door will then be wheeled. still in inverted position, to the airplan and the door actuating mechanism will be operated to swing the trunnions 6 and 1 into their doorinverted position shown in Figure 4. As in the previous case, the tow-bar H will be attached to the bomb bay door, and the thre hoists 12 will be connected to the door and to the draw bar as in the previous case. The loaded bomb bay door will then be hoisted into engagement with the trunnions 5 and I, still in its inverted position, and, after the castors, hoists and draw bar have been disconnected therefrom, and the bomb fins attached to the bomb, the actuatin mechanism will be operated to swing the door to its normal upright position with the bomb housed within the bomb bay as indicated in Figure 15.

While the bomb bay door of this invention is primarily intended for carrying bombs, it is also readily adaptable for other types of armament. Thus in Figure 14, the bomb bay door 5 is shown arranged for supporting a plurality of rockets 96 such as are used for ground strafing. In this particular case, a protective metal plate 97 is suitably attached to the interior of the bomb bay door and the rockets are supported in conventional manner from this plate. Plate 91 serves not only as a convenient support for the rockets but also protects th door structure from the deteriorating efiects of the rocket blasts. Thus the rockets can be carried within the bomb bay until such time as it is desired to fire them. when the door can be rapidly rotated to inverted position and the rockets fired.

It should be noted that in th modifications shown in Figures 11 and 16, the door will be provided with the guides, locking pins, seals, etc" as in Figures 1 through 10, but in the interest of simplifying the disclosure, these details have not been illustrated in the drawing.

The operation of applicants improved bomb bay construction is believed to be quite clear from the foregoing description. However, to

summarize briefly, assume that the airplane is on the a ound awaiting the loading of bombs therein and that the bomb bay door is detached from the airplane and resting on its casters on the ground. The bombs will be loaded onto the upper surfaceof the bomb bay door so that their bomb lugs are properly engaged in the slots of the books 53 and 59 of the associated bomb shackle assembly. The latter will, of course, be in its normal or cocked position as illustrated in Figure 9. The checks 62 will be adjusted so as to firmly support the bomb and the loaded bomb bay door will then be wheeled on its casters into position beneath the aircraft. The door actuating mechanism of the aircraft will, if not already so positioned, be operated into its normal position shown in Figure 2.

The bomb hoists 12 will beattached to their fittings within the aircraft as previously described and will be connected to the tow-bar and bomb bay door as illustrated in Figure 1. The loaded door will then be hoisted part-way up inot position and the casters removed therefrom. The hoisting operation will then be resumed and the door lifted into a position wherein the guides l3 move into engagement with the trunnions 6 and I at the ends of the bomb bay opening. The locking pins will then be engaged in the sockets of the trunnion members by suitable operation of the actuating panels 25 and the latter will then be secured in locked position by means of the fasteners 19. The electrical connections between the airplane and the bomb bay door will be made by connectors 65, 61 and the ejection cylinders 50 will be charged with compressed air from the storage cylinder 64. The hoists will then be disengaged and removed, and the tow-bar detached from the underside of the bomb bay door. The airplane will now be in condition for flight, with the bombs completely housed within the bomb bay.

The bomb bay door will be maintained in this normal position throughout the flight of the airplane until shortly before the beginning of the bombing run. At this time, the cylinders 32 will be actuated by a suitable fluid pressure control system (not shown) to quickly invert the door. The arrangement is such that the inverting operation occurs very rapidly so that the bomb bay opening is exposed only for a very brief time. As soon as the door reaches its fully inverted position (Figure 4) the opening is once again completely closed, thus minimizing the turbulence and drag which are so objectionable with prior bomb bay consrtuctions.

The bombs, now suspended externally of the aircraft, may thereafter be released one-by-one, or in any desired sequence, by suitable actuation of the bomb shackles 42. Ejection cylinders 50 are at all times urging the bomb away from the bomb bay door and, as soon as the shackle is released, the pistons 5| of the ejection cylinders will thrust the bomb outwardly away from the bomb bay door with considerable velocity. Moreover, as previously described, the arms 58 of the shackles will limit rearward movement of the associated bombs until they have moved a considerable distance away from the aircraft. Thus, tumbling of the bombs or collision thereof with one another or with adjacent structure ofthe aircraft is effectively avoided.

It should be noted that by providing for limited independent swinging of members l6 and I! of the forward trunnion I about pivot 18, any tendency of the rock shafts 8 to bind and thus pre vent or retard the rotation of the door will be eliminated. This is especially important, where, as in this case, a high speed airplane is involved, since with such aircraft there is considerable deflection of the fuselage during maneuvering of the craft and as a result thereof, there will frequently be relatively large changes in spacings between the trunnion axes H and [8 at opposite ends of the door which would otherwise-cause binding of the door and rock shafts. The described arrangement, by permitting relative longitudinal movement between the door and the forward rock shaft support, completely eliminates any such adverse action.

While the devices illustrated are intended primarily for carrying armament on a military aircraft, it is obvious that similar structure could be used for carrying other loads.

While several modifications have been illustrated and described, it is obvious that many other variations could be made without departing from the spirit and scope of the invention as defined by the appended claims.

We claim as our invention:

1. A closure for the bomb bay of an aircraft structure comprising a frame having secured to one side thereof a normally exterior surface sheet contoured to conform with and complete the faired shape of the portion of said aircraft structure in which is formed said bomb bay, the other side of said frame normally facing interiorly of said bomb bay, bomb shackle means for releasably supporting a bomb load on said interior surface of said frame, and means for selective rotation of said frame between normal and inverted positions, said frame in either position affording a closure for said bomb bay.

2. A closure for the bomb bay of an aircraft structure comprising a frame having secured to one side thereof a normally exterior surface contoured to conform with and complete the faired shape of the portion of said aircraft structure in which is formed said bomb bay, the other side of said frame normally facing interiorly of said bomb bay being equipped with bomb shackle means for releasably securing a bomb load, pivotal support means having pivotal axis extending generally along the line of flight, said pivotal support means comprising portions mounted on said closure and. on said aircraft structure so constructed and arranged to afford rotation of said closure from a normal to an inverted position about an axis medial of said closure, and means for selective rotation of said frame between normal and inverted positions, said frame in either position affording a complete closure for said bomb bay.

3. A closure for the bomb bay of an aircraft structure comprising a frame adapted to substantially fill the ventral opening of said bomb bay, said frame having secured to one side thereof a normally exterior surface sheet contoured to conform with and complete the faired shape of the portion of said aircraft structure in which is formed said bomb bay, said frame having a normally interior face having means mounted thereon adapted to releasably support a bomb load, a readily attachable pivotal means for securing said closure pre-loaded with said bomb load in operative position with respect to said bomb bay, and means cooperating with said pivotal means for selectively rotating said frame closure between normal and inverted positions,

9 said frame in either said positions afiording an Number effective closure for said bomb bay. 2,387,527 2,476,479 ALBERT T. WOOLLENS. 2,511,183 WERNER BUCHAL. 5 2,547,811

References Cited in the file of this patent UNITED STATES PATENTS gg Number Name Date 10 1,890,142 Boilam Dec. 6, 1932 2,362,361 Davis Nov. 7, 1944 Name Date Nagamatsu Oct. 23, 1945 Brack July 19, 1949 Van Norman June 13, 1950 Burnelli Apr. 3, 1951 FOREIGN PATENTS Country Date Great Britain June 2, 1943 

